Comparison of efficacy and safety between endoscopic submucosal dissection and transanal endoscopic microsurgery for the treatment of rectal tumor

Background/Aim: To compare the treatment efficacy and safety between endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) for the treatment of rectal epithelial tumors, including large adenoma, cancer, and subepithelial tumors (SET). Patients and Methods: We conducted a retrospective analysis of the medical records of 71 patients with rectal tumors who were treated with ESD (48 patients) or TEM (23 patients) from January 2013 to December 2015. The patient group comprised 56 patients with epithelial tumors and 15 patients with SET. Treatment efficacy such as en bloc resection, procedure time, local recurrence, hospital stay, additional procedure rate, and safety between the treatment groups were evaluated and analyzed. Results: There were no significant differences in tumor size, location, macroscopic appearance, and histological depth between ESD and TEM groups. For ESD compared to TEM in rectal epithelial tumors, en bloc resection rates were 95% vs. 93.7% and R0 resection rates were 92.5% vs. 87.5% (P = 0.617); in rectal SET, en bloc resection rates were 100% vs. 100% and R0 resection rates were 87% vs. 85% (P = 0.91). The procedure time was 71.5 +/- 51.3 min vs. 105.6 +/- 28.2 min (P = 0.016) for epithelial tumors and 32.13 +/- 13.4 min vs. 80.71 +/- 18.35 min (P = 0.00) for SET, respectively. Hospital stay was 4.3 +/- 1.2 days vs. 5.8 +/- 1.8 days (P = 0.001) for epithelial tumors and 4.1 +/- 4.1 days vs. 5.5 +/- 2 days (P = 0.42) for rectal SET, respectively. There were no significant differences between recurrence rates, additional procedure rates, and complications in the two groups. Conclusions: ESD and TEM are both effective and safe for the treatment of rectal epithelial tumors and SET because of favorable R0 resection rates and recurrence rates. However, the ESD group showed shorter procedure times and hospital stays than the TEM group. Therefore, ESD should be considered more preferentially than TEM in the treatment of large rectal epithelial tumors and SET.